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drivers/base: check errors
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Add lots of return-value checking.

<pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Andrew Morton authored and Greg Kroah-Hartman committed Sep 26, 2006
1 parent 3702264 commit f86db39
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Showing 4 changed files with 104 additions and 50 deletions.
2 changes: 1 addition & 1 deletion drivers/base/base.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ extern int cpu_dev_init(void);
extern int attribute_container_init(void);

extern int bus_add_device(struct device * dev);
extern void bus_attach_device(struct device * dev);
extern int bus_attach_device(struct device * dev);
extern void bus_remove_device(struct device * dev);
extern struct bus_type *get_bus(struct bus_type * bus);
extern void put_bus(struct bus_type * bus);
Expand Down
107 changes: 72 additions & 35 deletions drivers/base/bus.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -371,12 +371,20 @@ int bus_add_device(struct device * dev)
if (bus) {
pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
error = device_add_attrs(bus, dev);
if (!error) {
sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem");
sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
}
if (error)
goto out;
error = sysfs_create_link(&bus->devices.kobj,
&dev->kobj, dev->bus_id);
if (error)
goto out;
error = sysfs_create_link(&dev->kobj,
&dev->bus->subsys.kset.kobj, "subsystem");
if (error)
goto out;
error = sysfs_create_link(&dev->kobj,
&dev->bus->subsys.kset.kobj, "bus");
}
out:
return error;
}

Expand All @@ -386,14 +394,19 @@ int bus_add_device(struct device * dev)
*
* - Try to attach to driver.
*/
void bus_attach_device(struct device * dev)
int bus_attach_device(struct device * dev)
{
struct bus_type * bus = dev->bus;
struct bus_type *bus = dev->bus;
int ret = 0;

if (bus) {
device_attach(dev);
klist_add_tail(&dev->knode_bus, &bus->klist_devices);
ret = device_attach(dev);
if (ret >= 0) {
klist_add_tail(&dev->knode_bus, &bus->klist_devices);
ret = 0;
}
}
return ret;
}

/**
Expand Down Expand Up @@ -455,10 +468,17 @@ static void driver_remove_attrs(struct bus_type * bus, struct device_driver * dr
* Thanks to drivers making their tables __devinit, we can't allow manual
* bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
*/
static void add_bind_files(struct device_driver *drv)
static int __must_check add_bind_files(struct device_driver *drv)
{
driver_create_file(drv, &driver_attr_unbind);
driver_create_file(drv, &driver_attr_bind);
int ret;

ret = driver_create_file(drv, &driver_attr_unbind);
if (ret == 0) {
ret = driver_create_file(drv, &driver_attr_bind);
if (ret)
driver_remove_file(drv, &driver_attr_unbind);
}
return ret;
}

static void remove_bind_files(struct device_driver *drv)
Expand All @@ -476,35 +496,47 @@ static inline void remove_bind_files(struct device_driver *drv) {}
* @drv: driver.
*
*/
int bus_add_driver(struct device_driver * drv)
int bus_add_driver(struct device_driver *drv)
{
struct bus_type * bus = get_bus(drv->bus);
int error = 0;

if (bus) {
pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
error = kobject_set_name(&drv->kobj, "%s", drv->name);
if (error) {
put_bus(bus);
return error;
}
if (error)
goto out_put_bus;
drv->kobj.kset = &bus->drivers;
if ((error = kobject_register(&drv->kobj))) {
put_bus(bus);
return error;
}
if ((error = kobject_register(&drv->kobj)))
goto out_put_bus;

driver_attach(drv);
error = driver_attach(drv);
if (error)
goto out_unregister;
klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
module_add_driver(drv->owner, drv);

driver_add_attrs(bus, drv);
add_bind_files(drv);
error = driver_add_attrs(bus, drv);
if (error) {
/* How the hell do we get out of this pickle? Give up */
printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
__FUNCTION__, drv->name);
}
error = add_bind_files(drv);
if (error) {
/* Ditto */
printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
__FUNCTION__, drv->name);
}
}
return error;
out_unregister:
kobject_unregister(&drv->kobj);
out_put_bus:
put_bus(bus);
return error;
}


/**
* bus_remove_driver - delete driver from bus's knowledge.
* @drv: driver.
Expand All @@ -530,16 +562,21 @@ void bus_remove_driver(struct device_driver * drv)


/* Helper for bus_rescan_devices's iter */
static int bus_rescan_devices_helper(struct device *dev, void *data)
static int __must_check bus_rescan_devices_helper(struct device *dev,
void *data)
{
int ret = 0;

if (!dev->driver) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
device_attach(dev);
ret = device_attach(dev);
if (dev->parent)
up(&dev->parent->sem);
if (ret > 0)
ret = 0;
}
return 0;
return ret < 0 ? ret : 0;
}

/**
Expand All @@ -550,9 +587,9 @@ static int bus_rescan_devices_helper(struct device *dev, void *data)
* attached and rescan it against existing drivers to see if it matches
* any by calling device_attach() for the unbound devices.
*/
void bus_rescan_devices(struct bus_type * bus)
int bus_rescan_devices(struct bus_type * bus)
{
bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
}

/**
Expand All @@ -564,7 +601,7 @@ void bus_rescan_devices(struct bus_type * bus)
* to use if probing criteria changed during a devices lifetime and
* driver attachment should change accordingly.
*/
void device_reprobe(struct device *dev)
int device_reprobe(struct device *dev)
{
if (dev->driver) {
if (dev->parent) /* Needed for USB */
Expand All @@ -573,14 +610,14 @@ void device_reprobe(struct device *dev)
if (dev->parent)
up(&dev->parent->sem);
}

bus_rescan_devices_helper(dev, NULL);
return bus_rescan_devices_helper(dev, NULL);
}
EXPORT_SYMBOL_GPL(device_reprobe);

struct bus_type * get_bus(struct bus_type * bus)
struct bus_type *get_bus(struct bus_type *bus)
{
return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL;
return bus ? container_of(subsys_get(&bus->subsys),
struct bus_type, subsys) : NULL;
}

void put_bus(struct bus_type * bus)
Expand Down
37 changes: 27 additions & 10 deletions drivers/base/dd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,17 +38,29 @@
*
* This function must be called with @dev->sem held.
*/
void device_bind_driver(struct device * dev)
int device_bind_driver(struct device *dev)
{
if (klist_node_attached(&dev->knode_driver))
return;
int ret;

if (klist_node_attached(&dev->knode_driver)) {
printk(KERN_WARNING "%s: device %s already bound\n",
__FUNCTION__, kobject_name(&dev->kobj));
return 0;
}

pr_debug("bound device '%s' to driver '%s'\n",
dev->bus_id, dev->driver->name);
klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
sysfs_create_link(&dev->driver->kobj, &dev->kobj,
ret = sysfs_create_link(&dev->driver->kobj, &dev->kobj,
kobject_name(&dev->kobj));
sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
if (ret == 0) {
ret = sysfs_create_link(&dev->kobj, &dev->driver->kobj,
"driver");
if (ret)
sysfs_remove_link(&dev->driver->kobj,
kobject_name(&dev->kobj));
}
return ret;
}

/**
Expand Down Expand Up @@ -91,7 +103,11 @@ int driver_probe_device(struct device_driver * drv, struct device * dev)
goto ProbeFailed;
}
}
device_bind_driver(dev);
if (device_bind_driver(dev)) {
printk(KERN_ERR "%s: device_bind_driver(%s) failed\n",
__FUNCTION__, dev->bus_id);
/* How does undo a ->probe? We're screwed. */
}
ret = 1;
pr_debug("%s: Bound Device %s to Driver %s\n",
drv->bus->name, dev->bus_id, drv->name);
Expand Down Expand Up @@ -139,8 +155,9 @@ int device_attach(struct device * dev)

down(&dev->sem);
if (dev->driver) {
device_bind_driver(dev);
ret = 1;
ret = device_bind_driver(dev);
if (ret == 0)
ret = 1;
} else
ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
up(&dev->sem);
Expand Down Expand Up @@ -182,9 +199,9 @@ static int __driver_attach(struct device * dev, void * data)
* returns 0 and the @dev->driver is set, we've found a
* compatible pair.
*/
void driver_attach(struct device_driver * drv)
int driver_attach(struct device_driver * drv)
{
bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
}

/**
Expand Down
8 changes: 4 additions & 4 deletions include/linux/device.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,7 @@ struct bus_type {
extern int __must_check bus_register(struct bus_type * bus);
extern void bus_unregister(struct bus_type * bus);

extern void bus_rescan_devices(struct bus_type * bus);
extern int __must_check bus_rescan_devices(struct bus_type * bus);

/* iterator helpers for buses */

Expand Down Expand Up @@ -397,11 +397,11 @@ extern int device_rename(struct device *dev, char *new_name);
* Manual binding of a device to driver. See drivers/base/bus.c
* for information on use.
*/
extern void device_bind_driver(struct device * dev);
extern int __must_check device_bind_driver(struct device *dev);
extern void device_release_driver(struct device * dev);
extern int __must_check device_attach(struct device * dev);
extern void driver_attach(struct device_driver * drv);
extern void device_reprobe(struct device *dev);
extern int __must_check driver_attach(struct device_driver *drv);
extern int __must_check device_reprobe(struct device *dev);

/*
* Easy functions for dynamically creating devices on the fly
Expand Down

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